Methodi op cooling and drying air



Aug. 18,1931. rw. l.. r-'LElsHr-:R

Y METHOD OF COOLING AND DRYING'AIR Filed Nov.

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mmou ME Patented Aug. 1.8, 1931 UNiTED STATES PATENT ol-'EicE WALTER L. FLEISHER, F NEW YORK, N. Y., ASSIGNOR T0 THE COOLING & AIB, (JON-l DITIONING CORPORATION, OF NEW YORK, N. Y., A. CORPORATION OF NEW YORK METHOD or cooLINe ANnnaYINe .un

Application led November 80, 192'?.4 Serial No. $336,650.

This invention relates to ventilation and, more particularly, to Ventilating systems in which it is desired to maintain within an enclosure a degree of humidity materially below saturation.

In humidity control byair washing systems, where dehumidification is required, 1t

' is necessary to bring the air into contact with the wash water at or below the dew point to be maintained, in order to eiect the moisture extraction. This re ui'res the bringing of the air from the dry bul temperature to the dew point, as well as the extraction of the moisture and its heat content. This first is a waste of energy since the temperature must be subsequently raised in order to render the air suitable for Ventilating urposes. This requires' a considerable quantity of refrigeration, which does not represent usefulA work.

With such a system, moreover, the refrigeration itself becomes .expensive byy reason of the fact that the heat units are extracted from the moisture at comparatively low temperature. f

It is an object of this invention to produce a system in which satisfactory Ventilating conditions may be readily maintained with an economy of refrigeration.

In certain classes of ventilation the -problem is primaril -one of dehumidification and cooling. This is particularly true of theatre ventilation where, during operation, even in the winter months, the heat and moisture y given of by the occupants is, in itself, too se great for comfort.

In a system in which dehumidication is effected by spraying the air with water, the air leavinglthe spray chamber is at a certain dew point avingl a quantity of moisture suiteo able to correct t e room conditions. Where a suiicient'quantity of water is available from an external source, of a temperatureat or below the dew point to be maintained within the Washer, the cooling and dehydrating may 4B 'be e'ected without mechanical refrigeration.

In general, however, it is desirable to condition intensively a portion of thefair and subsequently dilute that conditioned air with unconditioned' air. Where such a system is employed it necessitates that the spray cham- The room may be provided with Bussum ber be maintained at astill lower temperature than where the air is all conditioned, and this requires a still lower temperature of the water supply.

In accordance with this invention it has been found that a silica `compound desi ated as silica gel possesses the property of a sorbing moisture from the air hygroscopicall even though the latter be far from saturate and without refrigeration. This makes it possible to extract the surplus moisture from the air without the necessity of lowering its temperature ar below the ultimate temperature desired, so that the direct cooling effect upon the airmay be confined to bringing the air to the desired sensible temperature after the proper quantity of moisture4 has been extracted.

The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the apparatus embod ing features of construction, combinations o elements and arrangement of parts which are adapted to effect such steps, all as exempliiied in the following detailed disclosure, and the scope of the application of which will be indicated in the claims. y

Fig. 1 is'a diagrammatic plan of a ventilating system embodying this invention.

Fig. 2 is a diagram of the control apparatus embodied therein.

In the ligures, the numeral 1 designates a room having an air inlet at 2 and outlet at 3. windows as shown at 4 through which a portion of the air introduced may escape. The air conditioning and Ventilating apparatus comprises generally a fresh air chamber 10 communieating with the outer air as shown at- 11 and having a connection fromthe air outlet "3 of the room through the medium of a conduit 12 controlled by a damper 13. Q

From the fresh air chamber there are pro,- vided three pathways to a fan chamber' 14 comprising a humidifier 15, a dehydrator 16 and a by-pass 17. These are each controlled by dam ersV designated as 18, 19 and 20, re-` spective y. The fan chamber contains a fan 21 for introducing the air from the fan chami ber into a mixing chamber 22 and a branch control of a dam er 24.

The air taken om the mixing chamber, is carried by a fan 25 through a tempering device 26 or introduction into the room 1 "through the inlet 2. This temperin device 0 contains both a heater 27 and a coo 'ng dev'izce 28. The heater is controlled by a valve 2 This cooling device is preferably arranged on the countercurrent system, having a plurality of pipesso arranged in series that the fresh cooling liquid is introduced to encoun- 'ter the already partly cooled air and thence passes on to encounter the uncooled air so that the coldest air encounters the coldest cooling liquid and the incoming or warmest air encounters the almost spent cooling liquid. This makes it possible to utilize the cooling effect for the maximum economy since it permits the delivery of air to the room substantially at the temperature of the cooling'fluid. The cooling liquid may thence be discharged from the cooler 28. It is preferably thereafter passed through a cooler 33 directly associated with the dehydrator beforel going to waste or before returning for refrigeration as the case may be, as will be hereinafter described.

The cooler 28 is supplied with a cooling liquid by a conduit 40 under control of a three-way valve 41which may supply liquid to the cooler, either from a `natural supply through a pipe 42'or from a refrigerator 43 through a conduit 44. This refrigerator may be operated through any suitable refrigerating 'machinery including, for example, a compresser 45, a condenser 46, and a liquid storage tank 47. f

Suitable 'wet and d bulb thermostats 50 and 51 may be provide in the return air duct 12 to control the operation of the device automatically. For the urpose of effecting a n further control over t e humidity and temperature, and to obtain that control with the greatest efiiciency, there is associated with the humidifier 15 a heater 32 in osition to warm the air as it enters the humidifier and thereby enable it 5to take up a greater quantity of moisture. This heater will be partic- `ularly useful where the outside temperatures are very low. It may be controlled by a valve 32a.

The dehydrator 16 is arranged to ex ose the air to a large surface of silica gel wiiich has the property of absorbing moisture from point. In so doing, however, the latent heat of the withdrawn moisture is given out as a sensible heat, raising the temperature of the the air even at temperatures' above the dew` ing coil 83 at the point in the system of the maximum temperature, that is immediately following the dehydrator itself. This cooler can most economically be placed in series with the cooler 28 to receive the cooling fluid which has already passed through the cooler 28, since in this manner the additional cooling effect obtained in the cooler- 33 results in the discharge of the cooling fiuid at ahigher temperature without the necessity of addilioral refrigeration or additional cooling The control apparatus for controlling the temperature under the influence vof the wet and dry bulb temperatures may be varied to meet conditions desired. For example, as illustrated in Fig. 2, the dry bulb thermostat maybe arranged to control the fiow of cold water to the air cooler 28 bv means of the valve 4l and to control the ow of steam to the air heater 27 by means of the valve 27a, so that as the dry bulb temperature rises, the heat from the hea-ter is cut ofi" and if this proves insufficient to lower the temperature, the cool water fromthe city supply may be introduced. If this be insufiicient, refrigerated water may be used. The wet bulb thermostat may be used to control the proportions. of air through silica gel cell and through the humidifier, increasing the proportions of the latter as the wet bulb temperature falls. This wet bulb thermostat may also be used to introduce steam into the tempering coil 32, if desired, as, for example, if the humidification from the humidifier acting upon the unheated air proves insufiicient.

If desired, the dry bulb thermostat may also be caused to introduce large quantities of return air when needed, in' order to increase the sensible heat to effect 'a saving in direct heating in the heater 32, and the wet bulb device may be caused to operate the damper 13 to introduce large quantities of return air through the humidifying system in order to effect a saving in the operation of the heater 32.

Since, in general, the Ventilating problem in the summer time is one of dehumidification and requires humidification only under certain conditions in the winter time, for certain seasons of the year, the sprays within the humidifying chamber may be closed down and the chamber 15 itself used solely as a by-pass around the silica gel cell. Similarly, during other seasons .of the year the silica gel may be omitted from the dehydrator and the dehydrating chamber itself used'as a by-pass around the humidifier. With a system contemplating this as its sole method of operation, the additional by-pass paratus.

' comprises extracting proportions.

' and dehydrating means in cells and the by-pass 17 permit an apportioning of the air between them which will control not only the moisture content of the air but also its physicall temperature. 4

It will be understood that the water for the sprays and the humidifier`15 may be either from a natural supply if there be a suiiicient supply of proper temperature, or. may itself b'e` taken from a refrigerating apity in the drawings, these details have een omitted therefrom.

Sincecertain changes in carrying out the above process and in the construction 'set forth, which embody the invention, may be made without departing from its scope, it is intended that all matter contained in the above description or shown in the accomanyi'ng drawings 'shall be interpreted as illustrative and not in a limiting sense.

It is Yalso understood that the following' claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is 1; In combination, conduit for conducting air humidifying means in one,

a chamber,a branched to said chamber, of said branches the other of Said branches, a mixing chamber into which each of said branches discharges, means for`conducting return air from a room to said mixingI chamber and means for adjusting the superheat of the air passing to thechamber. 2.' The method of vhumidity control which moisture from a,4 ortion of the air above the dew point, ad ing moisture to another portion of Athe air, mingling both said portions with other air and controlling the temperature and moisture content of the airvby regulating the said 3. The process of conditioning air which `comprises apporti'ning the ai'r between a .refrigerating dehydrator and a hygroscopic dehydrator mixing the ap ointedair and adjusting the proportions o the mixture-to control both temperature and humidity.

conditioning air which 4. The process of portion thereof. by

com rises dehydrating a of hygroscopicall min in the two ortions with each opt er an wit untreate air erature and humidity.

to control the tem conditioning'air which in- 5. A method o cludes withdrawing air from an enclosure,

passing a certain amount of such air througlh a humidiier, passing another lotion of e withdrawn air through a. dehy tor, mixing For the sake of avoiding com lex-v means .arranged to .take opening of enclosure, and a by-pass exte`n the humidified and dehydrated air, injecting a further amount of air withdrawn from the enclosure into the resultant mixture, and introducing the complete mixture to the enmeans arranged to the rear thereof, an`en' closure formed with inlet and outlet openings, means providing a passageway extending. from said outlet openin to the intake end of said de ydrating apparatus, a .byass in said passageway, and means provi ing a passageway connectedto said cooling means, said by-pass and to the intake opening of said"enclosure whereby and connected j l withdrawn unconditioned air is injected into the dehydrated cooled air and the resultant mixture cis introduced into said enclosure.

, 7 An apparatus of the character described including a dehydrating apparatus, -cooling the rear thereof, an enclosureV formed with inlet and outlet openings,means providing a passageway extending from vsaid outlet opening and connected to the intake -end of said dehydrating apparatus, a by-pass in said passageway, means providing a passageway connected to said cooling means, said by-pass and to the insaid enclosure whereby withdrawn unconditioned air is injected into the dehydrated cooled air andthe resultant mixture isintroducedY into said enclosure, and' means disposed within said last named pas- .sageway for controlling the sensible heat of the air flowing through the same, 8. An apparatus of the character described including, in combination, an enclosure -formed with inlet and outlet openings, a

assageway extending from said outlet opening, branches in communication with said passageway, a humidifying apparatus disposed within one of said brano rating apparatus disposed within another of the same, a mixing chamber connected to the outlet ends of both of said passageways, means for circulating air through said apparatus and passageways, means providing a further passageway extending from said mixing chamber to the intake opening of said ing from said first named passageway and in communication withsaid mixing chamber whereby to directly introduce untreated air into the mixture of humidied and dehydrated air.

In testimon whereof I aiix m` si ature. ALTER L. FL IS I R.

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